Protein After Illness, Surgery and for Pressure Injuries: Clinical Nutrition Overview
How clinical guidelines and reviews treat protein after illness or surgery and for pressure injuries, why this is a dietitian-led area, and what supplements have and have not shown.
Content last updated . This page has not been medically reviewed.
Overview
When someone is recovering from illness, an operation or a pressure injury (a pressure sore or bedsore), eating enough protein and calories can matter. It is also an area where the right amounts depend on the person, and where the hospital team, a dietitian or a doctor should lead. This page is an overview of what guidelines and reviews say. It is information, not advice for any one person, and it never replaces the plan your care team gives you.When to ask for help early
The NHS lists unintentional weight loss, such as a lot of weight lost over 3 to 6 months, among the signs to speak to a GP about. [1] It also says people aged 65 and over are particularly at risk, and weight loss is not an inevitable result of old age. [1] If a GP thinks you could be malnourished, they may refer you to a dietitian. [1] Poor appetite, trouble swallowing, wounds that are slow to heal or a pressure sore that is getting worse are all reasons to contact a clinician rather than self-treat with powders.What guidelines say
| Body and year | What it says | Notes |
|---|---|---|
| NICE (UK) CG32, updated 2017 | Nutrition support should be considered in people who are malnourished, and the guideline gives criteria such as unintentional weight loss greater than 10% within the last 3 to 6 months. [2] | Written for adults in hospital and the community. [2] |
| NICE, same guideline | For people not severely ill or injured and not at risk of refeeding syndrome, the suggested prescription includes 0.8 to 1.5 g of protein per kg per day. [2] | A suggested total intake from all sources, set by trained professionals, not a personal target. [2] |
| NICE, same guideline | Oral nutrition support can include fortified food with protein, carbohydrate and fat, snacks and oral nutritional supplements. [2] | Nutrition support teams are recommended in acute hospitals. [2] |
| ESPEN (Europe), surgery guideline, 2025 update | Early oral feeding is the preferred mode of nutrition for surgical patients. [3] Nutritional therapy is mandatory for any surgical patient at nutritional risk. [3] | It also lists avoiding long periods of preoperative fasting and early mobilization to support protein synthesis and muscle function. [3] |
| ESPEN, geriatrics guideline, 2022 | All older persons should routinely be screened for malnutrition. [4] Oral nutrition can be supported by counselling, food modification and oral nutritional supplements. [4] | Dietary restrictions should generally be avoided. [4] |
ESPEN reports that malnutrition and underfeeding are risk factors for postoperative complications. [3] The NHS says a doctor, nurse or dietitian may suggest nutritional drinks or supplements if food changes are not enough, and may suggest "fortified" foods high in calories and protein first. [1]
Pressure injuries: what trials show
A 2024 Cochrane review included 33 randomized trials with 7,920 participants. [5]| Question | What the review found | Strength of evidence |
|---|---|---|
| Preventing pressure ulcers with protein supplements | May result in little to no difference in incidence compared with a standard diet. [5] | Low certainty. [5] |
| Healing with energy, protein and micronutrient supplements | May slightly increase the number of healed ulcers. [5] | Low certainty. [5] |
| Collagen supplements for healing | Probably improved the mean change in ulcer area compared with placebo. [5] | One study, moderate certainty. [5] |
| Special diets such as protein-enriched diets | No study investigated these. [5] | Proper evidence not found in this review. |
The authors concluded that the benefits of nutritional interventions are uncertain, and may be little or none compared with standard nutrition or placebo. [5] A 2026 review of 18 trials found formulas enriched with protein, arginine, zinc, antioxidants and other nutrients appear promising, but evidence was limited by small samples, varied interventions and moderate methodological quality. [6] Single ingredients such as arginine are covered in L-Arginine and L-Citrulline. Collagen products are covered in Collagen for Skin, Joints and Bone.
Recovery after a hip fracture
A 2020 meta-analysis of 10 trials in 1,119 older patients with hip fracture undergoing rehabilitation found nutritional therapy showed a significant reduction in mortality, but the majority of studies were of low quality. [7] It tested nutritional therapy in general, not protein powder alone. [7]Frequently asked questions
How much protein is needed after surgery?
It depends on the person and procedure. NICE's suggested prescription for adults who are not severely ill is 0.8 to 1.5 g per kg per day from all sources, set by trained professionals. [2]
Do protein supplements heal pressure sores?
A 2024 Cochrane review found low-certainty evidence that energy, protein and micronutrient supplements may slightly increase healed ulcers, and little to no difference in prevention. [5]
Should I fast before surgery to be safe?
Follow your surgical team's instructions. ESPEN's guideline lists avoiding long periods of preoperative fasting as a key aspect of perioperative care. [3]
Are oral nutritional supplements the same as protein powder?
NICE lists oral nutritional supplements as one method within oral nutrition support alongside fortified food and snacks. [2]
Who should see a dietitian?
The NHS says a GP may refer people who could be malnourished to a dietitian. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: established role in clinical nutrition, evidence in at-risk groups, mixed, insufficient evidence, and "Proper evidence not found". Findings in people who are malnourished do not transfer to people who are well nourished, and the reverse.
Safety and who should ask
- Kidney disease: protein amounts may need adjusting. [8] People on dialysis may need more, because dialysis removes protein from the blood. [8] These decisions belong to the kidney team.
- Other conditions can also change what is suitable, so ask your team. See Protein and Kidney Disease.
- Before surgery: tell the team about every supplement; see Supplements Before Surgery. Interactions: Medication Interactions.
- Powders and drinks vary in quality; see Quality Testing and Certifications.
- Talk to a clinician, dietitian or pharmacist before adding protein or amino acid products during recovery.
References
- NHS (UK): Malnutrition, page last reviewed 23 May 2023. Read 2026-10-22.
- NICE (UK): Nutrition support for adults, clinical guideline CG32, recommendations, published 2006, last updated 4 August 2017. Read 2026-10-22.
- Weimann A et al. ESPEN guideline on clinical nutrition in surgery, update 2025. Clin Nutr 2025. Read 2026-10-22.
- Volkert D et al. ESPEN practical guideline: clinical nutrition and hydration in geriatrics. Clin Nutr 2022. Read 2026-10-22.
- Langer G et al. Nutritional interventions for preventing and treating pressure ulcers. Cochrane Database Syst Rev 2024. Read 2026-10-22.
- Yildirim D, Akin E. Does nutrition intervention prevent and heal pressure injury? A systematic review of randomized controlled trials. Adv Skin Wound Care 2026. Read 2026-10-22.
- Takahashi K et al. Nutritional therapy in older patients with hip fractures undergoing rehabilitation: a systematic review and meta-analysis. J Am Med Dir Assoc 2020. Read 2026-10-22.
- NIDDK (U.S. National Institutes of Health): Eating and nutrition for chronic kidney disease, last reviewed January 2025. Read 2026-10-22.